In the formation of extrusion dies for making honeycomb structures, the outlet face may be formed with a plurality of sawcuts such as disclosed in U.S. Pat. No. 3,790,654, where the cell pattern to be formed includes continuous linear walls extending transversely across the honeycomb structure, such as when forming honeycomb structures with square, rectangular or triangular cell shapes. However, when the desired cell configuration includes a hex shape as shown in U.S. Pat. No. 2,908,037 or a discontinuous diamond shape as shown in U.S. Pat. No. 3,846,197, methods other than sawcuts must be utilized to form the cell pattern. Such methods may include the incorporation of a plurality of individual cores which are manually positioned on a die body and bolted thereto as shown in the aforementioned U.S. Pat. No. 2,908,037, or the die may be formed of a plurality of laminated etched sheets of photosensitive glass or glass-ceramic material as disclosed in the aformentioned U.S. Pat. No. 3,846,197. However, the use of individually positioned core pins which are bolted to a die body not only requires the precise drilling and tapping of each individual hole for applying the core pins but is also costly and time consuming to manufacture. Further, the use of laminated etched photosensitive glass and glass-ceramic materials for forming a die is also not only expensive and time consuming to manufacture but is not particularly durable when extruding abrasive or viscous material.
Accordingly, the present invention has overcome the problem of forming an extrusion die for forming honeycomb structures by providing a method of initially fixturing a plurality of preshaped core pins in a desired orientation upon a die body so that said pins may be subsequently rigidly secured to the die body such as by welding.